#include<string.h>
#include<stdio.h>

int main()
{
	char srcStr[80]="56789",dstStr[80]="1234";
	int i,j=0;
	i = strlen(dstStr);
	
	while(srcStr[j]!='\0')
		dstStr[i++] = srcStr[j++];
	
	dstStr[i] = '\0';
	
	printf("%s\n",dstStr);
}
